Fiber optic attenuators are devices which reduce (attenuate) the strength of a fiber optic signal within a fiber optic network. Attenuators are usually used when the signal arriving at the receiver is too strong and hence may overpower the receiving elements. This may occur because of a mismatch between the transmitters/receivers (transceivers, media converters), or because the media converters are designed for a much longer distance than for which they are being used. Sometimes attenuators are also used for stress testing a network link by incrementally reducing the signal strength (increasing the dB attenuation) until the optical link fails, thus determining the signal's existing safety margin.